U.S. patent number 10,856,974 [Application Number 16/217,869] was granted by the patent office on 2020-12-08 for heart valve repair and replacement.
This patent grant is currently assigned to St. Jude Medical, Cardiology Division, Inc.. The grantee listed for this patent is St. Jude Medical, Cardiology Division, Inc.. Invention is credited to Thomas M. Benson, Peter N. Braido, Theodore Paul Dale, Mina S. Fahim, Mathias Charles Glimsdale, Mark Krans, Andrea N. Para.
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United States Patent |
10,856,974 |
Braido , et al. |
December 8, 2020 |
**Please see images for:
( Certificate of Correction ) ** |
Heart valve repair and replacement
Abstract
A prosthetic heart valve having an inflow end and an outflow end
includes a collapsible and expandable stent having a plurality of
commissure features, a plurality of first struts and a plurality of
second struts. The plurality of first struts define a substantially
cylindrical portion and the plurality of second struts have first
ends attached to the cylindrical portion and free ends projecting
radially outward from the cylindrical portion and configured to
couple to adjacent heart tissue to anchor the stent. A collapsible
and expandable valve assembly disposed within the stent has a
plurality of leaflets coupled to the commissure features.
Inventors: |
Braido; Peter N. (Wyoming,
MN), Fahim; Mina S. (Shoreview, MN), Benson; Thomas
M. (Minneapolis, MN), Dale; Theodore Paul (Corcoran,
MN), Para; Andrea N. (Centennial, TX), Krans; Mark
(Hopkins, MN), Glimsdale; Mathias Charles (St. Michael,
MN) |
Applicant: |
Name |
City |
State |
Country |
Type |
St. Jude Medical, Cardiology Division, Inc. |
St. Paul |
MN |
US |
|
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Assignee: |
St. Jude Medical, Cardiology
Division, Inc. (St. Paul, MN)
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Family
ID: |
56236094 |
Appl.
No.: |
16/217,869 |
Filed: |
December 12, 2018 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20190110894 A1 |
Apr 18, 2019 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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15177598 |
Jun 9, 2016 |
10179042 |
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62174690 |
Jun 12, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F
2/2469 (20130101); A61F 2/2409 (20130101); A61F
2/2418 (20130101); A61F 2220/0008 (20130101); A61F
2230/0006 (20130101); A61F 2230/0069 (20130101); A61F
2220/0016 (20130101) |
Current International
Class: |
A61F
2/24 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
19857887 |
|
Jul 2000 |
|
DE |
|
10121210 |
|
Nov 2002 |
|
DE |
|
102005003632 |
|
Aug 2006 |
|
DE |
|
202008009610 |
|
Dec 2008 |
|
DE |
|
0850607 |
|
Jul 1998 |
|
EP |
|
1000590 |
|
May 2000 |
|
EP |
|
1360942 |
|
Nov 2003 |
|
EP |
|
1584306 |
|
Oct 2005 |
|
EP |
|
1598031 |
|
Nov 2005 |
|
EP |
|
1926455 |
|
Jun 2008 |
|
EP |
|
2777616 |
|
Sep 2014 |
|
EP |
|
2847800 |
|
Jun 2004 |
|
FR |
|
2850008 |
|
Jul 2004 |
|
FR |
|
9117720 |
|
Nov 1991 |
|
WO |
|
9716133 |
|
May 1997 |
|
WO |
|
9832412 |
|
Jul 1998 |
|
WO |
|
9913801 |
|
Mar 1999 |
|
WO |
|
01028459 |
|
Apr 2001 |
|
WO |
|
0149213 |
|
Jul 2001 |
|
WO |
|
01054625 |
|
Aug 2001 |
|
WO |
|
01056500 |
|
Aug 2001 |
|
WO |
|
01076510 |
|
Oct 2001 |
|
WO |
|
0236048 |
|
May 2002 |
|
WO |
|
0247575 |
|
Jun 2002 |
|
WO |
|
02067782 |
|
Sep 2002 |
|
WO |
|
03047468 |
|
Jun 2003 |
|
WO |
|
2005070343 |
|
Aug 2005 |
|
WO |
|
06073626 |
|
Jul 2006 |
|
WO |
|
07071436 |
|
Jun 2007 |
|
WO |
|
08070797 |
|
Jun 2008 |
|
WO |
|
2010008548 |
|
Jan 2010 |
|
WO |
|
2010008549 |
|
Jan 2010 |
|
WO |
|
2010096176 |
|
Aug 2010 |
|
WO |
|
2010098857 |
|
Sep 2010 |
|
WO |
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2012068377 |
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May 2012 |
|
WO |
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Other References
"Direct-Access Valve Replacement", Christoph H. Huber, et al.,
Journal of the American College of Cardiology, vol. 46, No. 2,
(Jul. 19, 2005). cited by applicant .
"Minimally invasive cardiac surgery", M. J. Mack, Surgical
Endoscopy, 2006, 20:S488-S492, DOI: 10.1007/s00464-006-0110-8
(presented Apr. 24, 2006). cited by applicant .
"Percutaneous Aortic Valve Implantation Retrograde From the Femoral
Artery", John G. Webb et al., Circulation, 2006; 113:842-850 (Feb.
6, 2006). cited by applicant .
"Transapical aortic valve implantation: an animal feasibility
study"; Todd M. Dewey et al., the annals of thoracic surgery 2006;
82: 110-6 (Feb. 13, 2006). cited by applicant .
"Transapical approach for sutureless stent-fixed aortic valve
implantation: experimental results"; Th. Walther et al., European
Journal of Cardio-thoracic Surgery 29 (2006) 703-708 (Jan. 30,
2006). cited by applicant .
"Transapical Transcatheter Aortic Valve Implantation in Humans",
Samuel V. Lichtenstein et al., Circulation. 2006; 114: 591-596
(Jul. 31, 2006). cited by applicant .
Braido et al., U.S. Appl. No. 29/375,243, filed Sep. 20, 2010,
titled "Surgical Stent Assembly". cited by applicant .
Catheter-implanted prosthetic heart valves, Knudsen, L.L., et al.,
The International Journal of Artificial Organs, vol. 16, No. 5
1993, pp. 253-262. cited by applicant .
International Search Report for Application No. PCT/US2016/036560
dated Aug. 18, 2016. cited by applicant .
Is It Reasonable to Treat All Calcified Stenotic Aortic Valves With
a Valved Stent?, 579-584, Zegdi, Rachid, MD, PhD at al., J. of the
American College of Cardiology, vol. 51, No. 5, Feb. 5, 2008. cited
by applicant .
Moazami, N. et al., "Transluminal Aortic Valve Placement," ASAIO
Journal, Sep./Oct. 1996, pp. M381-M385, vol. 42. cited by applicant
.
Percutaneous aortic valve replacement: resection before
implantation, 836-840, Quaden, Rene et al., European J. of
Cardio-thoracic Surgery, 27 (2005). cited by applicant .
Textbook "Transcatheter Valve Repair", 2006, pp. 165-186. cited by
applicant .
Transluminal Catheter Implanted Prosthetic Heart Valves, Andersen,
Henning Rud, International Journal of Angiology 7:102-106 (1998).
cited by applicant .
Transluminal implantation of artificial heart valves, Andersen, H.
R., et al., European Heart Joumal (1992) 13, 704-708. cited by
applicant .
U.S. Appl. No. 29/375,260, filed Sep. 20, 2010. cited by
applicant.
|
Primary Examiner: Stewart; Alvin J
Attorney, Agent or Firm: Lerner, David, Littenberg, Krumholz
& Mentlik, LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No.
15/177,598, filed on Jun. 9, 2016, and claims the benefit of the
filing date of U.S. Provisional Patent Application No. 62/174,690
filed Jun. 12, 2015, the disclosures of which are hereby
incorporated herein by reference.
Claims
The invention claimed is:
1. A prosthetic heart valve having an inflow end and an outflow
end, comprising: a collapsible and expandable stent including a
plurality of first struts forming a substantially cylindrical
portion and a plurality of second struts that are curled when the
stent is in an expanded condition, each of the second struts having
a first end attached to the cylindrical portion, a free end
projecting radially outward from the cylindrical portion, and an
anchoring member at the free end for engaging adjacent heart
tissue; and a collapsible and expandable valve assembly coupled to
the stent and including a plurality of leaflets, wherein the
anchoring member comprises an elongated pivot head including a
substantially straight strut attached to the free end of the second
strut at a pivot point approximately in the middle of the
substantially straight strut, the elongated pivot head being
rotatable about the pivot point and within a plane from a first
position to a second position.
2. The prosthetic heart valve of claim 1, wherein at least some of
the first ends are attached to the stent adjacent the outflow
end.
3. The prosthetic heart valve of claim 1, wherein at least some of
the first ends are attached to the stent adjacent the inflow
end.
4. The prosthetic heart valve of claim 1, wherein at least some of
the first ends are attached to the stent adjacent the outflow end
and others of the first ends are attached to the stent adjacent the
inflow end.
5. The prosthetic heart valve of claim 4, wherein each of the free
ends projects toward a midsection of the stent between the inflow
end and the outflow end.
6. The prosthetic heart valve of claim 1, wherein the first
position is orthogonal to the free end of the second strut and the
second position is oblique to the free end of the second strut.
7. The prosthetic heart valve of claim 1, wherein the elongated
pivot head is shape-set to the second position.
8. The prosthetic heart valve of claim 1, wherein the valve
assembly and the stent are capable of replacing the function of at
least one of a native mitral valve or a native tricuspid valve.
9. A prosthetic heart valve having an inflow end and an outflow
end, comprising: a collapsible and expandable stent including a
plurality of first struts forming a substantially cylindrical
portion and a plurality of second struts that are curled when the
stent is in an expanded condition, each of the second struts having
a first end attached to the cylindrical portion at the outflow end,
a free end projecting radially outward from the cylindrical
portion, and an anchoring member at the free end; and a collapsible
and expandable valve assembly coupled to the stent and including a
plurality of leaflets, wherein the anchoring member is bell-shaped
and comprises a base having a first width attached to the free end
of the second strut having a second width less than the first width
and two arcuate atraumatic ends extending from the base radially
outward and away from the first end of the second strut.
10. The prosthetic heart valve of claim 9, wherein the anchoring
member defines a depressed portion for capturing chordae tendineae
between the two arcuate ends.
11. The prosthetic heart valve of claim 10, wherein the two arcuate
atraumatic ends are convex relative to the base.
Description
BACKGROUND OF THE INVENTION
The present disclosure relates to heart valve repair and, in
particular, to collapsible prosthetic heart valves. More
particularly, the present disclosure relates to devices and methods
for repairing and/or replacing the functionality of native valve
leaflets.
Diseased and/or defective heart valves may lead to serious health
complications. One method of addressing this condition is to
replace a non-functioning heart valve with a prosthetic valve.
Prosthetic heart valves that are collapsible to a relatively small
circumferential size can be delivered into a patient less
invasively than valves that are not collapsible. For example, a
collapsible valve may be delivered into a patient via a tube-like
delivery apparatus such as a catheter, a trocar, a laparoscopic
instrument, or the like. This collapsibility can avoid the need for
a more invasive procedure such as full open-chest, open-heart
surgery.
Collapsible prosthetic heart valves typically take the form of a
valve structure mounted on a stent. There are two types of stents
on which the valve structures are ordinarily mounted: a
self-expanding stent and a balloon-expandable stent. To place such
valves into a delivery apparatus and ultimately into a patient, the
valve must first be collapsed or crimped to reduce its
circumferential size.
When a collapsed prosthetic valve has reached the desired implant
site in the patient (e.g., at or near the annulus of the patient's
heart valve that is to be replaced by the prosthetic valve), the
prosthetic valve can be deployed or released from the delivery
apparatus and re-expanded to full operating size. For
balloon-expandable valves, this generally involves releasing the
entire valve, assuring its proper location, and then expanding a
balloon positioned within the valve stent. For self-expanding
valves, on the other hand, the stent automatically expands as the
sheath covering the valve is withdrawn.
SUMMARY OF THE INVENTION
In some embodiments, a prosthetic heart valve having an inflow end
and an outflow end, includes a collapsible and expandable stent
having a plurality of commissure features, a plurality of first
struts and a plurality of second struts. The plurality of first
struts define a substantially cylindrical portion of the stent and
the plurality of second struts have first ends attached to the
cylindrical portion and free ends projecting radially outward of
the cylindrical portion and configured to couple to adjacent heart
tissue to anchor the stent. A collapsible and expandable valve
assembly is disposed within the stent and has a plurality of
leaflets coupled to the commissure features.
BRIEF DESCRIPTION OF THE DRAWINGS
Various embodiments of the present disclosure are disclosed herein
with reference to the drawings, wherein:
FIG. 1 is a schematic cutaway representation of a human heart
showing a transapical delivery approach;
FIG. 2A is a schematic representation of a native mitral valve and
associated structures during normal operation;
FIG. 2B is a schematic representation of a native mitral valve
having a prolapsed leaflet;
FIG. 3 is a schematic longitudinal cross-section of one embodiment
of a prosthetic heart valve having a stent, a valve assembly, and a
frame;
FIG. 4 is a schematic longitudinal cross-section of one embodiment
of a prosthetic heart valve having a stent, a valve assembly, and
curling struts;
FIG. 5 is a schematic longitudinal cross-section of one embodiment
of a prosthetic heart valve having a stent, a valve assembly, and
curved struts;
FIGS. 6A-L are schematic representations of several variations of
the terminal ends of selected struts; and
FIG. 7 is a schematic longitudinal cross-section of one embodiment
of a prosthetic heart valve having a stent, a valve assembly, and
curling struts confined to a region adjacent the outflow
section.
Various embodiments of the present disclosure will now be described
with reference to the appended drawings. It is to be appreciated
that these drawings depict only some embodiments of the disclosure
and are therefore not to be considered limiting of its scope.
DETAILED DESCRIPTION
In conventional collapsible prosthetic heart valves, the stent is
usually anchored within the native valve annulus via radial forces
exerted by the expanding stent against the native valve annulus. If
the radial force is too high, damage may occur to heart tissue. If,
instead, the radial force is too low, the heart valve may move from
its implanted position, for example, into the left ventricle.
Because such anchoring partly depends on the presence of
calcification or plaque in the native valve annulus, it may be
difficult to properly anchor the valve in locations where plaque is
lacking (e.g., the mitral valve annulus).
In view of the foregoing, there is a need for further improvements
to the devices, systems, and methods for restoring and/or replacing
the function of a native heart valve, such as a mitral valve, a
tricuspid valve, an aortic valve, or a pulmonary valve. Among other
advantages, the present disclosure may address one or more of these
needs. While many of the examples disclosed herein are described
with reference to a specific valve (e.g., a mitral valve or a
tricuspid valve), it will be understood that many of the examples
are not so limited and that the concepts described apply equally to
other heart valves unless expressly limited herein.
Blood flows through the mitral valve from the left atrium to the
left ventricle. As used herein, the term "inflow," when used in
connection with a prosthetic mitral heart valve, refers to the end
of the heart valve closest to the left atrium when the heart valve
is implanted in a patient, whereas the term "outflow," when used in
connection with a prosthetic mitral heart valve, refers to the end
of the heart valve closest to the left ventricle when the heart
valve is implanted in a patient. When used in connection with a
prosthetic aortic valve, "inflow" refers to the end closest to the
left ventricle and "outflow" refers to the end closest to the
aorta. The same convention is applicable for other valves wherein
"inflow" and "outflow" are defined by the direction of blood flow
therethrough. "Trailing" is to be understood as relatively close to
the user, and "leading" is to be understood as relatively farther
away from the user. As used herein, the terms "proximal," "distal,"
"leading" and "trailing" are to be taken as relative to a user
using the disclosed delivery devices. "Proximal" or "trailing end"
are to be understood as relatively close to the user and "distal"
or "leading end" are to be understood as relatively farther away
from the user. Also, as used herein, the words "substantially,"
"approximately," "generally" and "about" are intended to mean that
slight variations from absolute are included within the scope of
the structure or process recited.
FIG. 1 is a schematic representation of a human heart 100. The
human heart includes two atria and two ventricles: a right atrium
112 and a left atrium 122, and a right ventricle 114 and a left
ventricle 124. As illustrated in FIG. 1, the heart 100 further
includes an aorta 110, and an aortic arch 120. Disposed between the
left atrium and the left ventricle is the mitral valve 130. The
mitral valve 130, also known as the bicuspid valve or left
atrioventricular valve, is a dual-flap that opens as a result of
increased pressure in the left atrium as it fills with blood. As
atrial pressure increases above that of the left ventricle, the
mitral valve opens and blood passes toward the left ventricle.
Blood flows through heart 100 in the direction shown by arrows
"B".
A dashed arrow, labeled "TA", indicates a transapical approach for
repairing or replacing heart valves, such as a mitral valve. In
transapical delivery, a small incision is made between the ribs and
into the apex of the left ventricle 124 at position "P1" in heart
wall 150 to deliver a prosthesis or device to the target site.
FIG. 2A is a more detailed schematic representation of a native
mitral valve 130 and its associated structures. Mitral valve 130
includes two flaps or leaflets, a posterior leaflet 136 and an
anterior leaflet 138, disposed between left atrium 122 and left
ventricle 124. Cord-like tendons known as chordae tendineae 134
connect the two leaflets 136, 138 to the medial and lateral
papillary muscles 132. During atrial systole, blood flows from the
left atrium to the left ventricle down the pressure gradient. When
the left ventricle contracts in ventricular systole, the increased
blood pressure in the chamber pushes the mitral valve to close,
preventing backflow of blood into the left atrium. Since the blood
pressure in the left atrium is much lower than that in the left
ventricle, the flaps attempt to evert to the low pressure regions.
The chordae tendineae prevent the eversion by becoming tense, thus
pulling the flaps and holding them in the closed position.
FIG. 2B is a schematic representation of mitral valve prolapse as
discussed above. Posterior leaflet 136 has prolapsed into left
atrium 122. Moreover, certain chordae tendineae have stretched and
others have ruptured. Because of damaged chordae 134a, even if
posterior leaflet 136 returns to its intended position, it will
eventually resume the prolapsed position due to being inadequately
secured. Thus, mitral valve 130 is incapable of functioning
properly and blood is allowed to return to the left atrium and the
lungs. It will be understood that in addition to chordae damage,
other abnormalities or failures may be responsible for mitral valve
insufficiency.
FIG. 3 is a longitudinal cross-section of prosthetic heart valve
200 in accordance with one embodiment of the present disclosure.
Prosthetic heart valve 200 is a collapsible prosthetic heart valve
designed to replace the function of the native mitral valve of a
patient. (See native mitral valve 130 of FIGS. 1-2.) Generally,
prosthetic valve 200 has inflow end 210 and outflow end 212.
Prosthetic valve 200 may be substantially cylindrically shaped and
may include features for anchoring, as will be discussed in more
detail below. When used to replace native mitral valve 130,
prosthetic valve 200 may have a low profile so as not to interfere
with atrial function.
Prosthetic heart valve 200 includes stent 250, which may be formed
from biocompatible materials that are capable of self-expansion,
such as, for example, shape-memory alloys including nitinol.
Alternatively, stent 250 may be formed of a material suitable for
forming a balloon-expandable stent. Stent 250 may include a
plurality of struts 252 that form closed cells 254 connected to one
another in one or more annular rows around the stent. Cells 254 may
all be of substantially the same size around the perimeter and
along the length of stent 250. Alternatively, cells 254 near inflow
end 210 may be larger than the cells near outflow end 212. Stent
250 may be expandable to provide a radial force to assist with
positioning and stabilizing prosthetic heart valve 200 within the
native mitral valve annulus.
Prosthetic heart valve 200 may also include valve assembly 260,
including a pair of leaflets 262 attached to a cylindrical cuff
264. Leaflets 262 replace the function of native mitral valve
leaflets 136 and 138 described above with reference to FIG. 2. That
is, leaflets 262 coapt with one another to function as a one-way
valve. It will be appreciated, however, that prosthetic heart valve
200 may have more than two leaflets when used to replace a mitral
valve or other cardiac valves within a patient. Valve assembly 260
of prosthetic heart valve 200 may be substantially cylindrical, or
may taper outwardly from outflow end 212 to inflow end 210. Both
cuff 264 and leaflets 262 may be wholly or partly formed of any
suitable biological material, such as bovine or porcine
pericardium, or polymers, such as PTFE, urethanes and the like.
When used to replace a native mitral valve, valve assembly 260 may
be sized in the range of about 20 mm to about 40 mm in diameter.
Valve assembly 260 may be secured to stent 250 by suturing to
struts 252 or by using tissue glue, ultrasonic welding or other
suitable methods.
An optional frame 300 may surround and house valve assembly 260 and
stent 250. Frame 300 may be formed of a braided material in various
configurations to create shapes and/or geometries for engaging
tissue and filling the spaces between valve assembly 260 and the
native valve annulus. As shown in FIG. 3, frame 300 includes a
plurality of braided strands or wires 305 arranged in
three-dimensional shapes. In one example, wires 305 form a braided
metal fabric that is both resilient and capable of heat treatment
to substantially set a desired preset shape. One class of materials
which meets these qualifications is shape-memory alloys. One
example of a suitable shape-memory alloy is nitinol. It is also
contemplated that wires 305 may comprise various materials other
than nitinol that have elastic and/or memory properties, such as
spring stainless steel, alloys such as Elgiloy.RTM.,
Hastelloy.RTM., and MP35N.RTM., CoCrNi alloys (e.g., trade name
Phynox), CoCrMo alloys, or a mixture of metal and polymer fibers.
Depending on the individual material selected, the strand diameter,
number of strands, and pitch may be altered to achieve desired
properties for frame 300.
In its simplest configuration, shown in FIG. 3, frame 300 may be
formed in a cylindrical or tubular configuration having inlet end
310, outlet end 312 and lumen 315 extending between inlet end 310
and outlet end 312 for housing stent 250 and valve assembly 260.
However, in certain embodiments stent 250 may be omitted, and valve
assembly 260 may be directly attached to frame 300 using any of the
techniques described above for attaching valve assembly 260 to
stent 250. Frame 300 may be radially collapsed from a relaxed or
preset configuration to a compressed or reduced configuration for
delivery into the patient. Once released after delivery, the
shape-memory properties of frame 300 may cause it to re-expand to
its relaxed or preset configuration. Frame 300 may also be locally
compliant in a radial direction such that a force exerted in the
direction of arrow F deforms a portion of the frame. In this
manner, irregularities in the native valve annulus may be filled by
frame 300, thereby preventing paravalvular leakage. Moreover,
portions of frame 300 may endothelialize and in-grow into the heart
wall over time, providing permanent stability and a low thrombus
surface.
FIG. 4 illustrates a variation in which prosthetic heart valve 400
includes outwardly curling struts to aid in its fixation to heart
tissue. Prosthetic heart valve 400 may extend between inflow end
210 and outflow end 212 and include all the elements disclosed
above including stent 250 formed of struts 252 defining cells 254,
and valve assembly 260 having leaflets 262 and cuff 264. Stent 250
may be substantially cylindrical as shown and may further include
two rows of curling struts 410a, 410b that project radially outward
from the general stent body to anchor the stent at a predetermined
location in the native valve annulus. A first row 420 of curling
struts 410a is disposed adjacent inflow end 210 of prosthetic heart
valve 400 and a second row 422 of curling struts 410b is disposed
adjacent outflow end 212. Each curling strut 410a, 410b has a first
end 412a connected to stent 250 and a free end 412b, with a curled
configuration between these ends. Curling struts 410a, 410b may be
formed of the same material as struts 252 and may be formed
integrally with stent 250 by laser cutting from the same tube that
forms stent 250 or separately formed and attached to stent 250
using welding techniques or other suitable methods. As shown in
FIG. 4, the first end 412a of each curling strut 410a is connected
to stent 250 at fixation points 430 at the bottom of the first full
row of cells 254 adjacent inflow end 210 of prosthetic heart valve
400 and the first end 412a of each curling strut 410b is connected
to stent 250 at fixation points 432 at the top of the last (i.e.,
bottom-most) full row of cells 254 adjacent outflow end 212 of the
prosthetic heart valve. It will be understood that other fixation
points (e.g., closer to inflow end 210 or further from inflow end
210) are possible.
As noted above, each curling strut 410a, 410b has a curled
configuration between its ends. Curling struts 410a initially
extend upward from fixation points 430 toward inflow end 210 before
bending outwardly and downwardly toward outflow end 212 to form a
substantially "fiddlehead" shape. Likewise, each curling strut 410b
initially extends downward from a fixation point 432 toward outflow
end 212 before bending outwardly and upwardly toward inflow end
210. Curling struts 410a,410b may be subjected to heat treatment to
substantially preset their desired curled shape. During the
delivery of prosthetic heart valve 400 into a patient, curling
struts 410a,410b may be distorted to a substantially linear
configuration within the sheath of a delivery device and may return
to their curled configuration when released from the sheath.
When heart valve 400 is implanted, first row 420 of curling struts
410a may engage upper portions of the native mitral valve (i.e.,
portions of the native mitral valve in left atrium 122) or the
atrial wall itself, while second row 422 of curling struts 410b may
engage lower portions of the native mitral valve (i.e., portions of
the native mitral valve in left ventricle 124) or the ventricular
wall itself. The engagement of curling struts 410a and 410b with
the surrounding native tissue may help to affix heart valve 400 in
the proper position in the native mitral valve annulus.
FIG. 5 illustrates another variation in which prosthetic heart
valve 500 includes projecting curved struts to aid in its fixation
to heart tissue. Prosthetic heart valve 500 may extend between
inflow end 210 and outflow end 212 and include all the elements
described above in connection with heart valve 400, including stent
250 formed of struts 252 defining cells 254, and valve assembly 260
having leaflets 262 and cuff 264. As shown, prosthetic heart valve
500 includes two rows of curved struts 510a, 510b.
A first row 520 of curved struts 510a is disposed adjacent inflow
end 210 of prosthetic heart valve 500 and a second row 522 of
curved struts 510b is disposed adjacent outflow end 212. Each
curved strut 510a, 510b has a first end 512a connected to stent
250, a free end 512b and a bowed configuration between these ends.
Curved struts 510a, 510b may be formed of the same material as
struts 252 and may be formed integrally with stent 250 by laser
cutting from the same tube that forms stent 250 or separately and
attached to stent 250 using welding or another suitable method.
Curved struts 510a, 510b may be between about 3.0 mm and about 8.0
mm in length. In at least some examples, curved struts 510a, 510b
are approximately 5.0 mm in length to aid in fixation.
Additionally, curved struts 510a, 510b may apply a small radial
force on the surrounding tissue. For example, the applied force may
be enough to maintain contact to avoid thrombus, but not enough
damage the tissue. In at least some examples, a radial force of
between about 0.1 N and about 2.0 N may be exerted by the curved
struts on the surrounding tissue. The force applied by curved
struts on surrounding tissues may also be selected by adjusting the
thickness and/or width of the curved struts. In some examples,
curved struts 510a, 510b may have a width that is between about 20%
to about 50% of struts 252. In some examples, curved struts 510a,
510b may have a wall thickness that is between about 20% to about
50% of struts 252.
In the example shown, the first end 512a of each curved strut 510a
is connected to stent 250 at the top of the first full row of cells
254 adjacent inflow end 210 of prosthetic heart valve 500 and the
first end 512a of each curved strut 510b is connected to stent 250
at the bottom of the last full row of cells 254 adjacent outflow
end 212 of the prosthetic heart valve. Each curved strut 510a
extends from its connection to stent 250 downwardly towards a
midsection M of heart valve 500 and radially outwardly from the
stent. Likewise, each curved strut 510b extends from its connection
to stent 250 upwardly toward midsection M and radially outwardly
from the stent. The connection of the curved struts to cells 254
does not have to be at the junction of two struts 252. Rather, as
shown in FIG. 5, prosthetic heart valve 500 may include curved
struts 510c that are coupled to selected struts 252a, 252b at
spaced distances from the junction between the two. In this
example, two curved struts 510c originate from one cell 254. This
configuration of two curved struts 510c per cell 254 may be termed
a "double takeoff" configuration and may be repeated at inflow end
210, outflow end 212, or both the inflow end and the outflow end.
This "double takeoff" configuration may also alternate with the
single curved struts 510a,510b, or replace all of the single curved
struts 510a,510b.
Each curved strut 510a, 510b, 510c may terminate in a substantially
circular eyelet 530 that forms a smooth and blunted shape at its
free end 512b to prevent trauma to heart tissue. As shown in
greater detail in FIG. 6A, strut 610a may terminate in circular
eyelet 611, having an aperture 612. Aperture 612 may be useful to
mate with portions of a delivery device for maneuvering and
positioning heart valve 500 during deployment. Instead of round
eyelets, curved struts 510a, 510b, 510c may have other smoothly
curved eyelets on their free ends, such as oval or elliptical
eyelets. Further, these smoothly curved structures need not include
an aperture, but may be in the form of a solid disk, oval or
ellipse. Alternatively, one or more of curved struts 510a, 510b
510c may include an anchoring feature at its free end as will be
described with reference to FIGS. 6B-L. In the following examples,
reference may be made to anchoring to heart tissue. It is intended
by this that the features described may couple to at least one of
an atrial wall, a ventricular wall, a native valve leaflet, heart
muscle, papillary muscles, tendons, chordae tendineae or any other
tissue adjacent a heart valve, such as a mitral valve or a
tricuspid valve. Unless otherwise noted, each of the features shown
in FIGS. 6A-6L and described below (or described above in the case
of the feature of FIG. 6A) may be provided on any one or more of
the curved struts of prosthetic heart valve 500.
FIG. 6B illustrates a variation in which strut 610b terminates in a
bell-shaped end 620 having a broad base 621 composed of two convex
ends 622 that are curved and disposed on either side of a middle
depressed portion 623. Without being bound to any particular
theory, it is believed that broad base 621 provides a larger
surface area for pushing against native tissue and reduces the risk
of trauma to heart tissue, and that depressed portion 623 may
provide a region to which chordae tendineae may attach. FIG. 6C
illustrates another variation in which strut 610c terminates in a
rounded end 625 having a narrowed neck 626 and a bulbous crown 627.
Narrowed neck 626 may add flexibility to strut 610c while bulbous
crown 627 provides an atraumatic contact point with body tissue.
FIG. 6D illustrates another variation in which strut 610d includes
a pivoting head 630 that is capable of rotating at pivot 631 to
alternate between a first position R1 and a second position R2
shown in phantom lines at an oblique angle to the strut. It will be
understood that pivoting head 630 may be heat set or otherwise
shape set so as to be disposed in position R2 during delivery of
prosthetic heart valve 500 into the patient, and may then return to
position R1 after deployment for anchoring. In FIG. 6E, strut 610e
terminates in arrow-shaped end 635 having two outwardly extending
wings 636 defining a cavity 637 between strut 610e and each wing.
Cavities 637 may capture certain portions of the heart tissue such
as, for example, chordae tendineae. FIG. 6F illustrates strut 610f
which terminates in corkscrew 640 formed of a helical member 641
that progressively narrows to a point 642. Corkscrew 640 may be
configured to engage certain heart tissue by having the tissue wrap
around the progressively narrowing member or by piercing the tissue
with point 642. A similar configuration, shown in FIG. 6G,
illustrates strut 610g having opposing teeth-like barbs 645,646
which capture heart tissue. Each barb 645, 646 is substantially
triangular and angled slightly away from the free end of strut 610g
such that the teeth are capable of grasping onto heart tissue when
implanted. FIG. 6H illustrates another example for anchoring a
strut to heart tissue. Strut 610h includes an energy-excitable
region 650, for example, having bio-glues like cyanoacrylates that
bonds to heart tissue when excited by an energy source (e.g., laser
energy, ultrasound, etc.). Instead of an energy-excitable region,
strut 610i of FIG. 6I includes a chemical bonding portion 655,
which includes a coating on strut 610i to aid in attachment to
heart tissue. In one example, chemical bonding region 655 includes
a biocompatible adhesive 656 that is coated onto one or more
surfaces of strut 610i. In FIG. 6J, strut 610j includes a region
660 having pores 661. Porous region 660 may be formed from a
different material than the remainder of strut 610j and may be
biodegradable. Additionally, an adhesive 662 or the like may be
added to pores 661 to aid in anchoring. FIG. 6K illustrates two
struts 610k1,610k2 each having a polarized region 665,666,
respectively. Polarized regions 665,666 may be magnetic and may
have opposite polarities such that, when brought close together,
struts 610k1,610k2 will be attracted to one another and
magnetically clamp onto tissue. In some examples, certain struts
that are used for anchoring may be divided into a first group of
struts having a first polarized region 610k1 and a second group of
struts having a second polarized region 610k2, the first and second
polarized regions being of opposite polarities. In at least some
examples, struts 610k1 having polarized regions 665 may be in a
first row and struts 610k2 having polarized regions 666 may be in a
second row, and the two rows may be disposed on opposite sides of
heart tissue. In FIG. 6L, strut 610l includes clamp 670 having
opposed clamps 671 defining a receiving portion 672 therebetween
for receiving a portion of heart tissue.
FIG. 7 illustrates another variation in which prosthetic heart
valve 700 includes projecting curved struts to aid in its fixation
to heart tissue. Prosthetic heart valve 700 may extend between
inflow end 210 and outflow end 212 and include all the elements
described above in connection with heart valve 400, including stent
250 formed of struts 252 defining cells 254, and valve assembly 260
having leaflets 262 and cuff 264. Similar to prosthetic heart valve
400 of FIG. 4, prosthetic heart valve 700 includes upper curling
struts 710a and lower curling struts 710b. Curling struts 710a,
710b may be between about 10 mm and about 20 mm. In contrast to
prosthetic heart valve 400, however, curling struts 710a-b are
arranged in pairs, with each pair originating at a single fixation
point 730. In this case, fixation points 730 are disposed close to
inflow end 210 (e.g., closer to the atrium when prosthetic heart
valve 700 is implanted) to minimize protrusion into the left
ventricular outflow tract. In some examples, fixation points 730
may be disposed equidistant between inflow end 210 and outflow end
212. Alternatively, fixation points 730 may be disposed closer to
outflow end 212 than to inflow end 210. In at least some examples,
curling struts 710a are longer than curling struts 710b and
fixation point 730 is disposed closer to outflow end 212 than
inflow end 210. Curling struts may apply a radial force on
surrounding tissue in the range described above with respect to
cured struts. In some examples, curling struts 710a, 710b may have
a width that is between about 20% to about 50% of struts 252. In
some examples, curling struts 710a, 710b may have a wall thickness
that is between about 20% to about 50% of struts 252. Though
leaflets 262 and stent 250 are illustrated in a simplified manner,
it will be appreciated that leaflets 262 may be attached to stent
250 at commissure features 770 and that fixation points 730 may be
disposed adjacent to or at the same longitudinal position as the
commissure features as shown, or anywhere between commissure
features 770 and outflow end 212.
According to the disclosure, a prosthetic heart valve has an inflow
end and an outflow end, and may include a collapsible and
expandable stent including a plurality of commissure features, a
plurality of first struts and a plurality of second struts, the
plurality of first struts defining a substantially cylindrical
projection and the plurality of second struts projecting radially
outward from the cylindrical portion and configured to couple to
adjacent heart tissue to anchor the stent, and a collapsible and
expandable valve assembly disposed within the stent and having a
plurality of leaflets coupled to the commissure features;
and/or
the plurality of second struts may include curved struts, the free
ends of the curved struts projecting toward a midsection of the
stent; and/or
the plurality of second struts may include curling struts, the
curling struts forming a fiddlehead shape between the first ends
and the second ends; and/or
the first ends may be disposed adjacent the outflow end; and/or
the first ends may be disposed at a longitudinal position between
the plurality of commissure features and the outflow end;
and/or
the free ends may terminate in at least one of a bell-shaped base,
a rounded end having a narrowed neck or a bulbous crown; and/or
the free ends may terminate in a pivoting head; and/or
the free ends may terminate in at least one of an arrow-shaped end,
a corkscrew, or a plurality of barbs; and/or
the free ends may terminate in at least one of a porous region, a
chemical bonding region, or an electrically excitable region;
and/or
the free ends may terminate in a region coated with a biocompatible
adhesive; and/or
the free ends of a first group of the second struts may have a
first polarity and the free ends of a second group of the second
struts may have a second polarity opposite a first polarity;
and/or
the valve assembly and the stent may be capable of replacing the
function of at least one of a native mitral valve and a native
tricuspid valve.
Although the invention herein has been described with reference to
particular embodiments, it is to be understood that these
embodiments are merely illustrative of the principles and
applications of the present invention. It is therefore to be
understood that numerous modifications may be made to the
illustrative embodiments and that other arrangements may be devised
without departing from the spirit and scope of the present
invention as defined by the appended claims.
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